The present invention relates to an assay method for detecting a biomaterial using a linear upconversion fluorescent property.
A target specimen (blood, sputum, etc.) or a detection substrate basically has fluorophores, which act as background noise in regards to fluorescence-based detection. In addition, when generally used conventional fluorescent particles are used, such background noise is also detected, and therefore, detection sensitivity of a target signal is limited.
One of the ways to minimize background noise is to utilize upconversion fluorescent materials, instead of general downconversion fluorescence ones, for a signaling label. Conventional upconversion nanoparticles (UCNPs) may have a size-independent maximum emission wavelength and facilitate multiple color emissions by transforming a host crystal and an RE doping material. Taking advantage of such characteristics, UCNPs have been used in flow cytometry, photodynamic therapy, diagnosis, etc., used as fluorescent labels for biological assays such as immunoassays and gene analysis, and also used in chemical detection/cell imaging.
However, in order to detect fluorescence using conventional UCNPs, a non-linear upconversion type of inorganic nanocrystal (absorbs biphotons and multiphotons) was mostly utilized, and a non-linear upconversion type of inorganic nanocrystal is detected with a laser, which is a high-power coherent excitation light source and is expensive, wherein detection is difficult.
For that reason, the inventors developed novel linear UCNPs that can be detected with a conventional LED by applying a linear upconversion fluorescent property to a method for detecting a biomaterial, and thus the present invention was completed.